I tend to think the Rangers' brass knows they are stuck and that not much is going to shake loose at the top of their roster, where the money and the NMCs live. Publicly signaling they are open for business does say that they would make a trade, sure, but even in the absence of actual moves it sends a shot across the bow to the team, especially those who might be complacent.
More messaging than a sign of a trade, I think. In time, they'll have to make some actual moves. Right now, they want the existing roster to play better because they know most of these guys are locked in for a while.